The present invention relates generally to the field of crating and palletizing objects, such as consumer goods, in shipping boxes, and specifically to a device capable of securing an upstanding crate to a recyclable pallet having structural uprights.
Near the end of a manufacturing conveyor line, finished product is often secured to pallets and crated for shipping. U.S. Pat. No. 5,823,349 describes a shipping container comprising a wooden base, a corrugated cardboard box that fits over the base, reinforcing material applied to the box adjacent to the base, and a plurality of fasteners which fasten the box to the base through the reinforcing material. While the described invention is a good system for attaching a cardboard crate to a wooden base, it provides little structural integrity and may collapse under a moderate overhead load. Shipping containers are typically stacked and sometimes require a high degree of structural rigidity. The present invention makes use of highly rigid structural uprights attached to the pallet which help support loads from all sides, as well as provide for additional fastener locations.
Traditionally, the task of securing the product and crate enclosure to the pallet has been carried out manually. The repeated motions of manual labor can become tedious, and depending on the size of the crates, such tasks can also become strenuous. Continued crating and moving of such containers can cause injury to workers. Further, depending on the output speed and configuration of the conveyor line, multiple workers may be required to properly palletize and crate the product. In an effort to reduce workforce size and injury costs, there has been a significant move toward automating this process by utilizing robots. As is known in the art, industrial robots may be fitted with various xe2x80x9cend of arm toolsxe2x80x9d or xe2x80x9cend-effectorsxe2x80x9d to accomplish different tasks, including driving fasteners into a connecting medium.
Robots have some advantages over human workers, such as being able to work continuously for days or weeks, while at the same time virtually eliminating human error. However, robotic arms lack the mobility of a human workforce. Due to a limited range of motion, a typical robot can only reach one or two sides of a container. Multiple robots have been needed to secure fasteners in all required locations. The present invention employs a turntable that rotates the container, thereby allowing a single robot to complete the entire task.
After the enclosure is properly fastened to the pallet, the container is ready for shipping. When it reaches the xe2x80x9cpoint of sale and deliveryxe2x80x9d destination, the pallet and enclosure are usually discarded. In the case of a distributor or retailer who receives a high volume of product, the vast amount of shipping materials creates disposal problems. Some dealers have even turned to burning the combustible materials because of the resources required to store and ship away the large amounts of refuse.
Disposing of the shipping materials can also be very wasteful. The pallet is usually well built to provide a stable platform for supporting the product and moving the container. Some large or heavy products make use of a metal pallet, which are more difficult to dispose of than those made of wood. Metal pallets are relatively more expensive than other shipping materials, and should be used multiple times to boost efficiency.
Reusing the shipping pallets requires some regulation to ensure they are still capable of providing an adequate supporting platform and secure fastening surface. The present invention employs a method of identifying said pallets before use in a way that allows the device to physically detect whether the pallet is still usable.
According to the present invention, the foregoing and other objects and advantages are attained by providing an apparatus or device capable of conveying a pallet and enclosure assembly into a work station, detecting if the pallet is usable, installing a number of fasteners in predetermined locations, and conveying the finished container out of the work station.
The process begins by manually securing a product to the pallet. This can be done in one or more ways, such as attaching straps to the pallet that wrap around said product. Next, one or more rigid U-shaped uprights are inverted and placed into pre-existing slots in the pallet. A bottomless cardboard enclosure is then lowered over the pallet, enclosing said product and said uprights.
The entire pre-loaded crate assembly may be brought to the work station by an infeed conveyor. The conveyor has pallet usage sensors that recognize how many times the current pallet has been used before, and photoeye sensors that detect the physical size of the incoming crate. This information is sent to the robot""s computer for calibration of the fastening sequence.
The pre-loaded container is delivered by an infeed conveyor to a turntable, where it is rotationally aligned to receive fasteners. The robot end-effector is equipped with at least one automatic screwdriver that receives threaded fasteners from a feeder mechanism. The preprogrammed robot and its screwdriver install said fasteners through the cardboard crate into the pallet and rigid uprights.
Because the robot has a limited range of motion, fastener installation is preferably accomplished in stages. The robot first inserts fasteners through the top of the crate into the rigid upright(s), then inserts fasteners on two adjacent sides of the container, into either the upright(s) or the pallet, depending on the preselected fastener location. The turntable then rotates the container 180xc2x0 so the robot can install fasteners into the two remaining sides. When this stage of robot activity is completed, the turntable reverses back to its original position. A conveyor then moves the finished container off the turntable and onto an exit conveyor. If any faults had been detected during the robot""s fastening operation, a label is placed onto the container as it leaves the work station indicating that a manual inspection and correction is required.